Curing agent composition for an epoxy resin compound, epoxy resin compound and multi-component epoxy resin system

Abstract

A curing agent composition for an epoxy resin compound useful for the chemical fastening of construction elements, an epoxy resin compound, and a multi-component epoxy resin system are provided. Methods for the chemical fastening of construction elements in boreholes and the use of a salt (S) as an accelerator in an epoxy resin compound for chemical fastening are provided, the epoxy resin compound including a benzoxazine-amine adduct and an amine which is reactive to epoxy groups.

Claims

1: A curing agent composition (B), comprising: a benzoxazine-amine adduct selected from the group consisting of substances according to formula Ia, substances according to formula Ib and mixtures thereof, having the following structures: ##STR00004## where R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are each independently selected from the group consisting of H, alkyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, arylalkyl, heteroalkyl, alkoxy, hydroxyl, hydroxyalkyl, carboxyl, halo, haloalkyl, amino, aminoalkyl, alkylcarbonyloxy, arylcarbonyloxy, alkoxycarbonyl, alkylcarbonyl, alkylsulfonylamino, aminosulfonyl, sulfonic acid, alkylsulfonyl groups, and also from combinations of two or more of these groups, wherein the groups are each unsubstituted or optionally substituted; where R.sup.6 and R.sup.7 each independently represent H or an amino, diamino or polyamino group selected from the group consisting of aliphatic, alicyclic, aromatic or araliphatic amine groups, and also combinations of two or more of these groups, wherein the groups are each unsubstituted or optionally substituted; where Z is selected from the group consisting of a direct bond, —C(O)—, —S—, —O—, —S(O)—, —S(O).sub.2—, —C(R.sup.8)(R.sup.9)—, —[C(R.sup.8)(R.sup.9)].sub.m—C(R.sup.8)(R.sup.9)—[C(R.sup.10)(R.sup.11)].sub.n—, —[C(R.sup.8)(R.sup.9)].sub.m—C(R.sup.8)(aryl)-[C(R.sup.10)(R.sup.11)].sub.n—, —[C(R.sup.8)(R.sup.9)].sub.m—C(O)—[C(R.sup.10)(R.sup.11)].sub.n—, —[C(R.sup.8)(R.sup.9)].sub.m—S—[C(R.sup.10)(R.sup.11)].sub.n—, —[C(R.sup.8)(R.sup.9)].sub.m—O—[C(R.sup.10)(R.sup.11)].sub.n—, —[C(R.sup.8)(R.sup.9)].sub.m—S(O)—[C(R.sup.10)(R.sup.11)].sub.n—, —[C(R.sup.8)(R.sup.9)].sub.m—S(O).sub.2—[C(R.sup.10)(R.sup.11)].sub.n—, a divalent heterocycle and —[C(R.sup.8)(R.sup.9)].sub.m-arylene-[C(R.sup.10)(R.sup.11)].sub.n—, where m and n are each independently between 0 and 10, where R.sup.8, R.sup.9, R.sup.10 and R.sup.11 each independently have the same meaning as the groups R.sup.1 to R.sup.5; and an amine which is reactive to epoxy groups and is selected from the group consisting of aliphatic, alicyclic, aromatic and araliphatic amines and which has on average per molecule at least two reactive hydrogen atoms bonded to a nitrogen atom, wherein the curing agent composition comprises at least one salt (S) selected from the group consisting of salts of nitric acid, salts of nitrous acid, salts of halogens, salts of trifluoromethanesulfonic acid and combinations thereof.

2: The curing agent composition according to claim 1, wherein R.sup.3 and R.sup.5 each represent H.

3: The curing agent composition according to claim 1, wherein Z is selected from the group consisting of a direct bond, —C(R.sup.8)(R.sup.9)—, —C(R.sup.8)(aryl)-, —C(O)—, —S—, —O—, —S(O)—, —S(O).sub.2—, a divalent heterocycle and —[C(R.sup.8)(R.sup.9)].sub.m-arylene-[C(R.sup.10)(R.sup.11)].sub.n—, where m and n are each independently between 0 and 5.

4: The curing agent composition (B) according to claim 1, wherein R.sup.3 and R.sup.5 each represent H, and wherein Z is selected from a direct bond or —C(R.sup.8)(R.sup.9)—, where R.sup.8 and R.sup.9 are each independently selected from H or C.sub.1-C.sub.4 alkyl groups, or together form a lactone group.

5: The curing agent composition according to claim 1, wherein the benzoxazine-amine adduct can be obtained by reacting a benzoxazine with an amine from the group of aliphatic and/or araliphatic amines, diamines, polyamines and mixtures thereof, wherein the benzoxazine has one of the following structures: ##STR00005##

6: The curing agent composition according to claim 1, wherein the amine reactive to epoxy groups is selected from the group consisting of 2,2,4- or 2,4,4-trimethyl-1,6-diaminohexane and mixtures thereof, 3-aminomethyl-3,5,5-trimethylcyclohexane (IPDA), 1,3-bis(aminomethyl)-cyclohexane (1,3-BAC), 1,4-bis(aminomethyl)-cyclohexane (1,4-BAC), 2-methyl-1,5-pentanediamine (DYTEK A), (3(4),8(9)bis(aminomethyl)dicyclo[5.2.1.02,6]decane and isomer mixtures thereof (TCD-diamine), aminomethyltricyclo[5.2.1.02.6]decane and isomer mixtures thereof (TCD-amine), 1,6-hexamethylene diamine, diethylene triamine (DETA), triethylene tetramine (TETA), tetraethylene pentamine (TEPA), pentaethylene hexamine (PEHA), 1,3-benzenedimethanamine (mXDA), 1,4-benzenedimethanamine (pXDA), N,N′-dimethyl-1,3-benzenedimethanamine, and mixtures of two or more thereof.

7: The curing agent composition according to claim 6, wherein the amine reactive to epoxy groups is selected from the group consisting of 3-aminomethyl-3,5,5-trimethylcyclohexane (IPDA), 2-methyl-1,5-pentanediamine (DYTEK A), 1,3-benzenedimethanamine (mXDA), 1,3-bis(aminomethyl)-cyclohexane (1,3-BAC) and mixtures thereof.

8: The curing agent composition according to claim 1, wherein the at least one salt (S) is selected from the group consisting of nitrate (NO.sub.3.sup.−), iodide (I.sup.−), triflate (CF.sub.3SO.sub.3.sup.−) and mixtures thereof.

9: The curing agent composition according to claim 1, wherein the at least one salt (S) is contained in the curing agent composition in an amount of from 0.1 to 15 wt. %, based on the total weight of the curing agent composition.

10: An epoxy resin compound, comprising: at least one curable epoxy resin; and a curing agent composition according to claim 1.

11: The epoxy resin compound according to claim 10, wherein the epoxy resin compound is a multi-component epoxy resin compound.

12: A multi-component epoxy resin system, comprising: an epoxy resin component (A), and a curing agent component, wherein the epoxy resin component (A) contains a curable epoxy resin, and the curing agent component comprises a benzoxazine-amine adduct and an amine which is reactive to epoxy groups, wherein the benzoxazine-amine adduct is selected from the group consisting of substances according to formula Ia, substances according to formula Ib and mixtures thereof, having the following structures: ##STR00006## where R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are each independently selected from the group consisting of H, alkyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, arylalkyl, heteroalkyl, alkoxy, hydroxyl, hydroxyalkyl, carboxyl, halo, haloalkyl, amino, aminoalkyl, alkylcarbonyloxy, arylcarbonyloxy, alkoxycarbonyl, alkylcarbonyl, alkylsulfonylamino, aminosulfonyl, sulfonic acid, alkylsulfonyl groups, and also from combinations of two or more of these groups, wherein the groups are each unsubstituted or optionally substituted: where R.sup.6 and R.sup.7 each independently represent H or an amino, diamino or polyamino group selected from the group consisting of aliphatic, alicyclic, aromatic or araliphatic amine groups, and also combinations of two or more of these groups, wherein the groups are each unsubstituted or optionally substituted; where Z is selected from the group consisting of a direct bond, —C(O)—, —S—, —O—, —S(O), —S(O).sub.2—, —C(R.sup.8)(R.sup.9)—, —[C(R.sup.8)(R.sup.9)].sub.m—C(R.sup.8)(R.sup.9)—[C(R.sup.10)(R.sup.11)].sub.n—, —[C(R.sup.8)(R.sup.9)].sub.m—C(R.sup.8)(aryl)-[C(R.sup.10)(R.sup.11)].sub.n, —[C(R.sup.8)(R.sup.9)].sub.m—C(O)—[C(R.sup.10)(R.sup.11)].sub.n, —[C(R.sup.8)(R.sup.9)].sub.m—S—[C(R.sup.10)(R.sup.11)].sub.n, —[C(R.sup.8)(R.sup.9)].sub.m—O—[C(R.sup.10)(R.sup.11)].sub.n—, —[C(R.sup.8)(R.sup.9)].sub.m—S(O)—[C(R.sup.10)(R.sup.11)].sub.n—, —[C(R.sup.8)(R.sup.9)].sub.m—S(O).sub.2—[C(R.sup.10)(R.sup.11)].sub.n—, a divalent heterocycle and —[C(R.sup.8)(R.sup.9)].sub.m-arylene-[C(R.sup.10)(R.sup.11)].sub.n—, where m and n are each independently between 0 and 10, where R.sup.8, R.sup.9, R.sup.10 and R.sup.11 each independently have the same meaning as the groups R.sup.1 to R.sup.5; and the amine which is reactive to epoxy groups is selected from the group consisting of aliphatic, alicyclic, aromatic and araliphatic amines and has on average per molecule at least two reactive hydrogen atoms bonded to a nitrogen atom, wherein a salt (S) selected from the group consisting of salts of nitric acid, salts of nitrous acid, salts of halogens, salts of trifluoromethanesulfonic acid and combinations thereof is contained in the epoxy resin component (A) and/or in the curing agent component.

13: The multi-component epoxy resin system according to claim 12, wherein the salt (S) is contained in the curing agent component.

14: A method for the chemical fastening of a construction element in boreholes, the method comprising: chemical fastening of the construction element with an epoxy resin compound according to claim 10.

15: A method, comprising: accelerating an epoxy resin compound with at least one salt (S) selected from the group consisting of salts of nitric acid, salts of nitrous acid, salts of halogens, salts of trifluoromethanesulfonic acid and combinations thereof, wherein the epoxy resin compound comprises a benzoxazine-amine adduct and an amine which is reactive to epoxy groups, wherein the benzoxazine-amine adduct is selected from the group consisting of substances according to formula Ia, substances according to formula Ib and mixtures thereof, having the following structures: ##STR00007## where R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are each independently selected from the group consisting of H, alkyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, arylalkyl, heteroalkyl, alkoxy, hydroxyl, hydroxyalkyl, carboxyl, halo, haloalkyl, amino, aminoalkyl, alkylcarbonyloxy, arylcarbonyloxy, alkoxycarbonyl, alkylcarbonyl, alkylsulfonylamino, aminosulfonyl, sulfonic acid or alkylsulfonyl groups, and also from combinations of two or more of these groups, wherein the groups are each unsubstituted or optionally substituted: where R.sup.6 and R.sup.7 each independently represent H or an amino, diamino or polyamino group selected from the group consisting of aliphatic, alicyclic, aromatic or araliphatic amine groups, and also combinations of two or more of these groups, wherein the groups are each unsubstituted or optionally substituted; where Z is selected from the group consisting of a direct bond, —C(O)—, —S—, —O—, —S(O), —S(O).sub.2—, —C(R.sup.8)(R.sup.9)—, —[C(R.sup.8)(R.sup.9)].sub.m—C(R.sup.8)(R.sup.9)—[C(R.sup.10)(R.sup.11)].sub.n—, —[C(R.sup.8)(R.sup.9)].sub.m—C(R.sup.8)(aryl)-[C(R.sup.10)(R.sup.11)].sub.n—, —[C(R.sup.8)(R.sup.9)].sub.m—C(O)—[C(R.sup.10)(R.sup.11)].sub.n—, —[C(R.sup.8)(R.sup.9)].sub.m—S—[C(R.sup.10)(R.sup.11)].sub.n—, —[C(R.sup.8)(R.sup.9)].sub.m—O—[C(R.sup.10)(R.sup.11)].sub.n—, —[C(R.sup.8)(R.sup.9)].sub.m—S(O)—[C(R.sup.10)(R.sup.11)].sub.n—, —[C(R.sup.8)(R.sup.9)].sub.m—S(O).sub.2—[C(R.sup.10)(R.sup.11)].sub.n—, a divalent heterocycle and —[C(R.sup.8)(R.sup.9)].sub.m-arylene-[C(R.sup.10)(R.sup.11)].sub.n—, where m and n are each independently between 0 and 10, where R.sup.8, R.sup.9, R.sup.10 and R.sup.11 each independently have the same meaning as the groups R.sup.1 to R.sup.5, and wherein the amine which is reactive to epoxy groups is selected from the group consisting of aliphatic, alicyclic, aromatic and araliphatic amines and has on average per molecule at least two reactive hydrogen atoms bonded to a nitrogen atom.

16: A method for the chemical fastening of a construction element in boreholes, the method comprising: chemical fastening of the construction element with a multi-component epoxy resin system according to claim 12.

17: A cured compound obtained by curing the epoxy resin compound according to claim 10.

Description

EXAMPLE: EEW=158 G/MOL

[0078] Amine/epoxy resin mixture having a maximum Tg2: 1 g amine with 4.65 g epoxy resin

[00001]$\mathrm{AHEW}\left(\mathrm{amine}\right)=\frac{158}{4.65}=34$

[0079] The present invention further relates to an epoxy resin compound which comprises at least one curable epoxy resin and a curing agent composition as described above. The epoxy resin compound is preferably a multi-component epoxy resin compound, more preferably a two-component epoxy resin compound.

[0080] A large number of the compounds known to a person skilled in the art and commercially available for this purpose, which contain on average more than one epoxy group, preferably two epoxy groups, per molecule can be used as a curable epoxy in the epoxy resin component (A). These epoxy resins may be both saturated and unsaturated as well as aliphatic, alicyclic, aromatic or heterocyclic, and may also have hydroxyl groups. They may also contain substituents which do not cause disruptive secondary reactions under the mixing or reaction conditions, for example alkyl or aryl substituents, ether groups and the like. Trimeric and tetrameric epoxies are also suitable in the context of the invention.

[0081] The epoxy resins are preferably glycidyl ethers which are derived from polyhydric alcohols, in particular from polyhydric phenols such as bisphenols and novolacs, in particular those having an average glycidyl group functionality of 1.5 or greater, in particular 2 or greater, for example from 2 to 10.

[0082] Examples of the polyhydric phenols used to prepare the epoxy resins are resorcinol, hydroquinone, 2,2-bis-(4-hydroxyphenyl)propane (bisphenol A), isomer mixtures of dihydroxyphenylmethane (bisphenol F), tetrabromobisphenol A, novolacs, 4,4′-dihydroxyphenylcyclohexane and 4,4′-dihydroxy-3,3′-dimethyldiphenylpropane.

[0083] The epoxy resin is preferably a diglycidyl ether of bisphenol A or bisphenol F or a mixture thereof. Liquid diglycidyl ethers based on bisphenol A and/or F having an epoxy equivalent weight (EEW) of from 150 to 300 g/EQ are particularly preferably used.

[0084] Further examples are hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, bisphenol A epichlorohydrin resins and/or bisphenol F epichlorohydrin resins, for example having an average molecular weight of Mn≤2000 g/mol.

[0085] The present invention further relates to a multi-component epoxy resin system comprising an epoxy resin component (A) and a curing agent component, the epoxy resin component (A) containing a curable epoxy resin, and the curing agent component being a benzoxazine-amine adduct which is selected from the group consisting of substances according to formula Ia, substances according to formula Ib or mixtures thereof and an amine which is reactive to epoxy groups. The multi-component epoxy resin system also comprises a salt (S) selected from salts of nitric acid, salts of nitrous acid, salts of halogens, salts of trifluoromethanesulfonic acid and combinations thereof, the salt (S) being contained in the epoxy resin component (A) and/or in the curing agent component. The multi-component epoxy resin system is preferably a two-component epoxy resin system.

[0086] The above statements apply to the curable epoxy resin, the substances according to formula Ia and formula Ib and the salt (S).

[0087] The salt (S) used as an accelerator can be contained in the epoxy resin component (A) or in the curing agent component or in both the epoxy resin component (A) and the curing agent component. It is preferable for the salt (S) to be contained at least in the curing agent component, preferably only in the curing agent component. In this case, the curing agent composition described above is used in the multi-component epoxy resin system.

[0088] The proportion of epoxy resin in the epoxy resin component (A) is >0 wt. % to 100 wt. %, preferably from 10 to 70 wt. % and particularly preferably from 30 wt. % to 60 wt. %, based on the total weight of the epoxy resin component (A).

[0089] In addition to the epoxy resins, the epoxy resin component (A) may optionally contain at least one reactive diluent. Glycidyl ethers of aliphatic, alicyclic or aromatic monoalcohols or in particular polyalcohols having a lower viscosity than epoxies containing aromatic groups are used as reactive diluents. Examples of reactive diluents are monoglycidyl ethers, e.g. o-cresyl glycidyl ether, and glycidyl ethers having an epoxide functionality of at least 2, such as 1,4-butanediol diglycidyl ether (BDDGE), cyclohexanedimethanol diglycidyl ether and hexanediol diglycidyl ether, as well as tri- or higher glycidyl ethers, such as glycerol triglycidyl ether, pentaerythritol tetraglycidyl ether, trimethylolpropane triglycidyl ether (TMPTGE), or trimethylolethane triglycidyl ether (TMETGE), with trimethylolethane triglycidyl ether being preferred. Mixtures of two or more of these reactive diluents can also be used, preferably mixtures containing triglycidyl ethers, particularly preferably as a mixture of 1,4-butanediol diglycidyl ether (BDDGE) and trimethylolpropane triglycidyl ether (TMPTGE) or 1,4-butanediol diglycidyl ether (BDDGE) and trimethylolethane triglycidyl ether (TMETGE).

[0090] The reactive diluents are preferably present in an amount of from 0 wt. % to 60 wt. %, more preferably from 1 wt. % to 20 wt. %, based on the total weight of the epoxy resin component (A).

[0091] Suitable epoxy resins and reactive diluents can also be found in the standard reference from Michael Dombusch, Ulrich Christ and Rob Rasing, “Epoxidharze,” Vincentz Network GmbH & Co. KG (2015), ISBN 13: 9783866308770. These compounds are included here by reference.

[0092] In a further embodiment, the epoxy resin component (A) may contain a co-accelerator, provided that this is compatible with the epoxy resins. Tertiary amines, imidazole or tertiary aminophenols, organophosphines, Lewis bases or acids such as phosphoric acid esters, or mixtures of two or more thereof, may be used as co-accelerators, for example. As mentioned above, these co-accelerators can also be present in the curing agent composition (B).

[0093] The proportion of the epoxy resin component (A) in relation to the total weight of the multi-component epoxy resin system is preferably from 5 wt. % to 90 wt. %, more preferably from 20 wt. % to 80 wt. %, even more preferably from 30 wt. % to 70 wt. % or most preferably from 40 wt. % to 60 wt. %.

[0094] The epoxy resins can have an EEW of from 120 to 2000 g/Eq, preferably from 140 to 400 g/Eq, in particular from 150 to 300 g/Eq. Mixtures of a plurality of epoxy resins may also be used.

[0095] The proportion of the curing agent composition (B) in relation to the total weight of the multi-component epoxy resin system is preferably from 10 wt. % to 95 wt. %, more preferably from 15 wt. % to 80 wt. %, even more preferably from 15 wt. % to 60 wt. % or particularly preferably from 20 wt. % to 40 wt. %.

[0096] Furthermore, the epoxy resin component (A) can contain conventional additives, in particular adhesion promoters and fillers, as already described for the curing agent composition.

[0097] The adhesion promoter can be contained in an amount of up to 10 wt. %, preferably from 0.1 to 5 wt. %, particularly preferably from 1.0 to 5.0 wt. %, based on the total weight of the epoxy resin component (A).

[0098] The inorganic fillers described above are preferably used as fillers. The fillers may also be present in one or all components of the multi-component mortar compound.

[0099] The proportion of fillers is preferably from 0 wt. % to 90 wt. %, for example from 10 wt. % to 90 wt. %, preferably from 15 wt. % to 75 wt. %, more preferably from 20 wt. % to 50 wt. %, and even more preferably from 25 wt. % to 40 wt. %, based on the total weight of the mortar compound.

[0100] Further conceivable additives to the multi-component epoxy resin compound are also thixotropic agents such as optionally organically after-treated fumed silica, bentonites, alkyl- and methylcelluloses and castor oil derivatives, plasticizers such as phthalic or sebacic acid esters, stabilizers, antistatic agents, thickeners, flexibilizers, curing catalysts, rheology aids, wetting agents, coloring additives such as dyes or pigments, for example for different staining of components for improved control of their mixing, as well as wetting agents, desensitizing agents, dispersants and other control agents for the reaction rate, or mixtures of two or more thereof.

[0101] Non-reactive diluents (solvents) may preferably also be contained in an amount of up to 30 wt. %, based on the total weight of the relevant component (epoxy resin component and/or curing agent component), for example from 1 wt. % to 20 wt. %. Examples of suitable solvents are alcohols, such as methanol or ethanol, lower alkyl ketones such as acetone, di lower alkyl lower alkanoyl amides such as dimethylacetamide, lower alkyl benzenes such as xylenes or toluene, phthalic acid esters or paraffins.

[0102] Further additives of this kind may preferably be added in proportions by weight of a total of from 0 wt. % to 40 wt. %, based on the total weight of the epoxy resin component.

[0103] The multi-component epoxy resin system is preferably present in cartridges or film pouches which are characterized in that they comprise two or more separate chambers in which the epoxy resin component (A) and the curing agent composition (B) of the mortar compound are separately arranged so as to prevent a reaction.

[0104] For the use as intended of the multi-component epoxy resin system, the epoxy resin component (A) and the curing agent component are discharged out of the separate chambers and mixed in a suitable device, for example a static mixer or dissolver. The mixture of epoxy resin component (A) and curing agent component is then introduced into the previously cleaned borehole by means of a known injection device. The component to be fastened is then inserted into the epoxy resin compound and aligned. The reactive constituents of the curing agent component react with the epoxy resins of the resin component (A) by polyaddition such that the epoxy resin compound cures under environmental conditions within a desired period of time, preferably within hours.

[0105] Components A and B are preferably mixed in a ratio that results in a balanced stoichiometry according to the EEW and AHEW values.

[0106] The epoxy resin compound according to the invention or the multi-component epoxy resin system according to the invention is preferably used for construction purposes. The expression “for construction purposes” refers to the structural adhesion of concrete/concrete, steel/concrete or steel/steel or one of said materials with other mineral materials, to the structural strengthening of components made of concrete, brickwork and other mineral materials, to reinforcement applications with fiber-reinforced polymers of building objects, to the chemical fastening of surfaces made of concrete, steel or other mineral materials, in particular the chemical fastening of construction elements and anchoring means, such as anchor rods, anchor bolts, (threaded) rods, (threaded) sleeves, reinforcing bars, screws and the like, in boreholes in various substrates, such as (reinforced) concrete, brickwork, other mineral materials, metals (e.g. steel), ceramics, plastics, glass, and wood. Most particularly preferably, the epoxy resin compounds according to the invention and the multi-component epoxy resin system according to the invention are used for chemically fastening anchoring means.

[0107] The present invention also relates to a method for the chemical fastening of construction elements in boreholes, an epoxy resin compound according to the invention or a multi-component epoxy resin system according to the invention being used as described above for the chemical fastening of the construction elements. The method according to the invention is particularly suitable for the structural adhesion of concrete/concrete, steel/concrete or steel/steel or one of said materials with other mineral materials, for the structural strengthening of components made of concrete, brickwork and other mineral materials, for reinforcement applications with fiber-reinforced polymers of building objects, for the chemical fastening of surfaces made of concrete, steel or other mineral materials, in particular the chemical fastening of construction elements and anchoring means, such as anchor rods, anchor bolts, (threaded) rods, (threaded) sleeves, reinforcing bars, screws and the like, in boreholes in various substrates, such as (reinforced) concrete, brickwork, other mineral materials, metals (e.g. steel), ceramics, plastics, glass, and wood. The method according to the invention is very particularly preferably used for the chemical fastening of anchoring means.

[0108] The present invention also relates to the use of at least one salt (S) selected from the group consisting of salts of nitric acid, salts of nitrous acid, salts of halogens, salts of trifluoromethanesulfonic acid and combinations thereof as an accelerator in an epoxy resin compound for the chemical fastening of construction elements, in particular for anchoring fastening elements in boreholes. The epoxy resin compound comprises at least one benzoxazine-amine adduct according to formula Ia and/or formula Ib as described above and an amine which is reactive to epoxy groups. It is preferable for the epoxy resin compound to be in the form of a multi-component epoxy resin system which comprises the epoxy resin component (A) described above and the curing agent component. It is also preferable for the salt (S) to be contained in the curing agent component and thus for a curing agent composition (B) as described above to be used.

[0109] The use of at least one salt (S) within the meaning of the present invention as an accelerator in an epoxy resin compound, in particular in a multi-component epoxy resin system, makes it possible to considerably shorten the curing time of the epoxy resin compound and furthermore to ensure sufficient pull-out strength after only four to six hours. Furthermore, the cured epoxy resin compound has excellent pull-out strength at elevated temperatures and in the water-filled borehole.

[0110] The present invention also relates to the use of at least one salt (S) selected from the group consisting of salts of nitric acid, salts of nitrous acid, salts of halogens, salts of trifluoromethanesulfonic acid and combinations thereof as an accelerator in an epoxy resin compound, in particular in a multi-component epoxy resin system. The epoxy resin compound comprises at least one benzoxazine-amine adduct according to formula Ia and/or formula Ib as described above and an amine which is reactive to epoxy groups. It is preferable for the epoxy resin compound to be in the form of a multi-component epoxy resin system which comprises the epoxy resin component (A) and curing agent component described above. It is also preferable for the salt (S) to be contained in the curing agent component and thus for a curing agent composition (B) to be used. The use of at least one salt (S) within the meaning of the present invention as an accelerator in an epoxy resin compound, in particular in a multi-component epoxy resin compound and more preferably in the curing agent component of the multi-component epoxy resin compound, makes it possible in particular to increase the pull-out strength of the epoxy resin compound at elevated temperatures, for example in a temperature range of from 35° C. to 50° C.

[0111] Furthermore, the use of at least one salt (S) within the meaning of the present invention as an accelerator in an epoxy resin compound, in particular in a multi-component epoxy resin compound and more preferably in the curing agent component of the multi-component epoxy resin compound, makes it possible to increase the pull-out strength of the epoxy resin compounds in water-filled boreholes.

[0112] Further advantages of the invention can be found in the following description of preferred embodiments, which are not understood to be in anyway limiting, however. All embodiments of the invention can be combined with one another within the scope of the invention.

EXAMPLES

[0113] Epoxy Resin Component (A)

[0114] Starting Materials

[0115] In the examples, the bisphenol A-based and bisphenol F-based epoxy resins commercially available under the names Araldite GY 240 and Araldite GY 282 (Huntsman), respectively, were used as the epoxy resins.

[0116] 3-glycidyloxypropyl-trimethoxysysilane available under the name Dynalsylan GLYMO™ (Evonik Industries) was used as the adhesion promoter.

[0117] The 1,4-butanediol-diglycidyl ether and trimethyolpropane-triglycidyl ether commercially available under the names Araldite DY-026 and Araldite™ DY-T (Huntsman), respectively, were used as the reactive diluents.

[0118] The liquid components were premixed by hand. Subsequently, quartz (Millisil™ W12 from Quarzwerke Frechen) was added as a filler and fumed silica (Cab-O-Sil™ TS-720 from Cabot Rheinfelden) was added as a thickener and the mixture was stirred in the dissolver (PC laboratory system, volume 1 L) for 10 minutes at a negative pressure of 80 mbar at 3500 rpm.

[0119] The composition of the epoxy resin component (A) used in the examples is given in table 1 below.

TABLE-US-00001 TABLE 1 Composition of epoxy resin component (A) Percent by Substance Function weight [wt. %] 3-glycidyloxypropyl- Adhesion promoter 2.6 trimethoxysysilane Bisphenol A-based epoxy resin Epoxy resin 31.3 Bisphenol F-based epoxy resin Epoxy resin 16.7 1,4-butanediol-diglycidyl ether Reactive diluent 6.0 Trimethyolpropane-triglycidyl ether Reactive diluent 6.0 Quartz Filler 34.7 Silicic acid Thickener 2.7 EEW [g/Eq] 256

[0120] Curing Agent Composition (B)

[0121] Starting Materials

[0122] The benzoxazines used to prepare the curing agent composition (B) are available under the trade names Araldite MT 35600 CH (benzoxazine A; CAS number: 154505-70-1), Araldite MT 35700 CH (benzoxazine F; CAS number: 214476-06-9) and Araldite MT 35710 FST (benzoxazine FST: mixture of benzoxazine F and 3-phenyl-3,4-dihydro-2H-benzo[e][1,3]oxazine) from Huntsman Advanced Materials, Basel, Switzerland.

[0123] 1,3-cyclohexanedimethanamine (1,3-BAC), m-xylylenediamine (mXDA) from MGC, Japan, 2-piperazino-ethylamine (N-AEP) from Sigma Aldrich Germany, isophorone diamine (IPDA) from Evonik Degussa, Germany and 2-methlypentamethylenediamine (Dytek A) from Invista, the Netherlands, were used as amines for preparing the curing agent composition (B).

[0124] 3-aminopropyl-triethoxysilane, which is available under the trade name Dynasylan AMEO from Evonik Degussa, was used as an adhesion promoter.

[0125] Quartz (Millisil™ W12 from Quarzwerke Frechen) and calcium aluminate cement (Secar 80 from Kemeos SA) were used as a filler and fumed silica (Cab-O-Sil™ TS-720 from Cabot Rheinfelden) was used as a thickener.

[0126] Preparation of the Benzoxazine-Amine Adduct

[0127] The corresponding benzoxazine was dissolved in excess amine and the solution was heated, with stirring, for 24 hours to 55° C. (for B2: 80° C.). A yellow to yellow-brown viscous solution was obtained (benzoxazine/amine adduct approx. 60% in amine).

[0128] The following benzoxazine-amine adducts were prepared:

[0129] B1: Benzoxazine FST/1,3-BAC, 60% in 1,3-BAC

[0130] B2: Benzoxazine F/IPDA, 60% in IPDA

[0131] B3: Benzoxazine F/mXDA, 60% in mXDA

[0132] B4: Benzoxazine A/N-AEP, 60% in N-AEP

[0133] Accelerator

[0134] The constituents given in table 2 below were used to prepare the salts (S) or accelerators used in the curing agent composition (B).

TABLE-US-00002 TABLE 2 List of salts (S) or accelerators used Salt (S) or accelerator Trade name Manufacturer Calcium nitrate Calcium nitrate tetrahydrate Sigma-Aldrich Calcium carbonate Calcium carbonate Sigma-Aldrich Nitric acid 70% Nitric acid Sigma-Aldrich Sodium iodide Sodium iodide Sigma-Aldrich Calcium triflate Calcium trifluoromethanesulfonate Sigma-Aldrich 2,4,6- Ancamin K54 Evonik tris(dimethylaminomethyl)phenol, bis[(dimethylamino)methyl]phenol

[0135] The salts calcium nitrate and sodium iodide were used as solutions in glycerol (1,2,3-propanetriol, CAS No. 56-81-5, Merck, G). To prepare the calcium nitrate solution, 400.0 g calcium nitrate tetrahydrate was added to 100.0 g glycerol and stirred at 50° C. until completely dissolved (3 hours). The solution prepared in this way contained 80.0% calcium nitrate tetrahydrate. To prepare the sodium iodide solution, 36.4 g sodium iodide was added to 63.6 g glycerol and stirred at 50° C. until completely dissolved. The solution prepared in this way contained 36.4% sodium iodide.

[0136] Calcium triflate was dissolved as a solid in the amine of the particular curing agent.

[0137] A calcium nitrate/nitric acid solution was also used as the accelerator. To prepare this solution, 52.6 g calcium carbonate was slowly added to 135.2 g nitric acid and then stirred for 5 minutes.

Examples 1 to 7

[0138] To prepare the curing agent composition (B) according to examples 1 to 7 below, the relevant benzoxazine-amine adduct was used as a solution in the relevant amine and diluted with the relevant further amine in accordance with the tables below. The accelerator was added, and quartz powder and silicic acid were then added and stirred in the dissolver (PC laboratory system, volume 1 L) for 10 minutes under a vacuum at 3500 rpm.

[0139] The composition of the curing agent compositions (B) prepared in this way is given in table 3 below:

TABLE-US-00003 TABLE 3 Composition of the curing agent composition (B) in wt. % Example 1 2 3 4 5 6 7 Benzoxazin- B1 27.3 — — — — — — amine B2 — 26.6 — — — — — adduct B3 — — 28.9 — — — — B4 — — — 52.3 28.5 26.25 28.9 Amine IPDA 27.3 26.6 — — — — — 1,3-BAC — — 28.9 — — — — N-AEP — — — 4.75 — — — DYTEK A — — — — 28.5 26.25 28.9 Salt (S) Calcium nitrate 6.25 7.6 — 3.75 3.75 — — Calcium — — 3.0 — — — — nitrate/nitric acid Sodium iodide — — — — — 8.3 — Calcium triflate — — — — — — 3.0 Adhesion promoter 2.4 2.4 2.4 2.4 2.4 2.4 2.4 Quartz 19.4 19.5 19.5 19.5 19.55 19.5 19.5 Calcium aluminate 13.0 13.0 13.0 13.0 13.0 13.0 13.0 cement Thickener 4.3 4.3 4.3 4.3 4.3 4.3 4.3 AHEW [g/Eq] 87 103 73 127 73 80 72

Comparative Example 1 to 5

[0140] To prepare the curing agent composition (B) according to comparative examples 1 to 5 below, the relevant benzoxazine-amine adduct was used as a solution in the relevant amine and diluted with the relevant further amine in accordance with the tables below. The accelerator was added, and quartz powder and silicic acid were then added and stirred in the dissolver (PC laboratory system, volume 1 L) for 10 minutes at a negative pressure of 80 mbar at 3500 rpm.

[0141] Table 4 shows the composition of the curing agent components (B) from comparative examples 1 to 5.

TABLE-US-00004 TABLE 4 Composition of the curing agent composition (B) in wt. % Comparative Example 1 2 3 4 5 Benzoxazin- B1 29.2 — — — — amine B2 — 29.2 — — — adduct B3 — — 29.2 — — B4 — — — 53.5 29.2 Amine IPDA 29.2 29.2 — — — 1,3-BAC — — 29.2 — — N-AEP — — — 4.9 — DYTEK A — — — — 29.2 Accelerator Ancamin K54 2.4 2.4 2.4 2.4 2.4 Adhesion 2.4 2.4 2.4 2.4 2.4 promoter Quartz 19.5 19.5 19.5 19.5 19.5 Calcium 13.0 13.0 13.0 13.0 13.0 aluminate cement Thickener 4.3 4.3 4.3 4.3 4.3 AHEW 81 93 72 124 72 [g/Eq]

[0142] Mortar Compounds and Pull-Out Tests

[0143] The epoxy resin component (A) and the curing agent composition (B) were mixed in a speed mixer in a ratio resulting in a balanced stoichiometry according to the EEW and AHEW values. The mixture was poured into a one-component cartridge as far as possible without bubbles, and was immediately injected into the borehole made for the pull-out tests.

[0144] The pull-out strength of the mortar compounds obtained by mixing the epoxy resin component (A) and the curing agent composition (B) according to the above examples was determined using a high-strength threaded anchor rod M12 according to ETAG 001 Part 5, which was doweled into a hammer-drilled borehole having a diameter of 14 mm and a borehole depth of 69 mm with the relevant mortar compound in C20/25 concrete. The boreholes were cleaned by means of compressed air (2×6 bar), a wire brush (2×) and again by compressed air (2×6 bar).

[0145] The boreholes were filled up, by two thirds from the bottom of the borehole, with the mortar compound to be tested in each case. The threaded rod was pushed in by hand. The excess mortar was removed using a spatula.

[0146] The curing time in test 1 was 4 hours at 21° C. In test 2, the curing time was 6 hours at 21° C. In test 3, the curing time was 24 hours at 21° C.

[0147] The failure load was determined by centrally pulling out the threaded anchor rod with close support. The load values obtained with the mortar compounds using a curing agent composition (B) according to examples 1 to 7 and comparative examples 1 to 5 are shown in table 5 below.

TABLE-US-00005 TABLE 5 Determination of the load values Load value [N/mm.sup.2] Pull-out Test Examples Comparative examples tests number 1 2 3 4 5 6 7 1 2 3 4 5 4 h curing 1 12.7  4.6 25.5 19.3 25.0 21.8 26.7  0.1  0.0  1.1 16.3  2.5 6 h curing 2 15.1 13.1 33.0 24.8 30.0 27.8 30.7  5.2  0.3 23.9 25.5 23.4 24 h curing 3 31.6 33.2 35.9 28.9 36.2 34.3 34.1 31.6 29.5 36.0 27.8 33.2

[0148] The pull-out tests show that the mortar compounds of the examples according to the invention each have significantly higher load values after a curing time of only 4 hours than the mortar compounds of the comparative examples. The mortar compounds of comparative examples 1, 2, 4 and 5 were still soft after a curing time of 4 hours. The pull-out tests after 6 hours show the further progress of the curing of the mortar compounds, with the examples according to the invention each having significantly higher load values after 6 hours of curing time than the mortar compounds of the comparative examples.